FRACTURE OF RANDOM FIBER NETWORKS WITH NONCENTRAL FORCES

The breakdown of random networks on triangular lattice is studied numerically. For the interactions the Born Hamiltonian is used, which gives the problem a tensorial character in contrast with the scalar-type random resistor and central force networks. Also, networks built out of fibres of constant length are studied. This gives rise to short-range oriented correlations and a wider binomial distribution for the local elastic moduli. The results show novel effects between the competition of the weakening caused by increased fluctuations in bond strengths and the reinforcement by fibres. These phenomena are studied by averaged breakdown forces, averages over broken bonds during the fracture processes and stress-strain curves. A generic stress-strain curve is presented, which also shows how the tensorial nature of the local interactions reduces the gap between the fracture of random networks and real materials.